/Engine/Plugins/Experimental/PCG/Source/PCG/Public/Metadata/PCGAttributePropertySelector.h
Extra trait to specify to the deserializer that those two classes can be deserialized using the old class.
template<> struct TStructOpsTypeTraits< FPCGAttributePropertyInputSelector > : public [TStructOpsTypeTraitsBase2< FPCGAttributePropertyInputSelector >](API\Runtime\CoreUObject\UObject\TStructOpsTypeTraitsBase2)